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Methane leakage modeling tool

See the climate impact of switching to natural gas

We developed this modeling tool to explore the climate implications of reducing emissions from natural gas systems in the context of a switch towards natural gas-fueled technologies.

Use the model to create scenarios comparing a hypothetical “policy case” to the baseline case by adjusting leak rates, fuel mix (power and transport sectors), and efficiency in the power sector (see below for sample scenarios).

The results of your choices are depicted in both a graph and a table over time. These results show the potential change in “climate influence” — or, more precisely, the change in cumulative radiative forcing relative to total 2010 U.S. greenhouse gas emissions over 100 years.

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Sample scenarios

EDF has set a goal of reducing natural gas leakage rates to 1% across the supply chain. Reductions of that magnitude from our assumed leak rate of 2.8% would have substantial climate benefits across all time frames: from a 5.9% to 2.7% reduction in net radiative forcing relative to 2010 U.S. greenhouse gas emissions over 20 and 100-year time horizons respectively. Climate benefits are attributable mostly to the non-electricity residential, commercial and industrial sectors—although some is also attributable to the power sector.

Scenario 2: Fuel switch to natural gas

In this scenario, coal-fired power generation is reduced by one-third and entirely replaced by natural gas-fired generation. In the transport sector, the share of natural gas is increased to 50% in both light-duty and heavy-duty vehicle fleets. There is no reduction in the leak rate, which stays at 2.8%. The model shows that for the first 13 years, the switch to natural gas would result in climate damage. After that, there would be slight benefits that increase over time, from a 0.7- 4.2% reduction in net radiative forcing relative to 2010 U.S. greenhouse gas emissions over 20- and 100-year time horizons, respectively. While there are climate benefits from the power sector switch across all time frames, the initial climate damages result from the fuel switch in the transport sector. The light-duty switch only becomes beneficial around 72 years after conversion, while the switch in the heavy-duty fleet results in climate damages over the entire 200-year time frame examined.

The model also allows the user to determine the “cross-over leak rate,” or the leak rate at which a fuel switch would be beneficial to the climate across all time frames. For the fuel switch in the light-duty and heavy-duty fleets to be beneficial across all time frames, the well-to-wheels leak rates would need to be below 1.6% and 1%, respectively.

Scenario 3: Fuel switch to natural gas plus leak rate reduction

This is a combination of Scenarios 1 and 2. As in Scenario 2, coal-fired generation is reduced by a third and replaced entirely by natural gas; transport sector fuel mixes are shifted to 50% natural gas. However, in this scenario, the well-to-wheels leak rate is reduced from 2.8% to 1%, as in Scenario 1. This scenario illustrates the importance of reducing leak rates in the context of a fuel mix shift to natural gas. With leak rates reduced, the fuel switch provides large climate benefits across all time frames, from a 11.3% to 9.2% reduction in net radiative forcing relative to 2010 U.S. greenhouse gas emissions over 20 and 100-year time horizons, respectively. The transport sector fuel switch now results in climate benefits as well, though very small (between 0.1 and 0.2%) for the heavy-duty fleet.

Scenario 4: Fuel switch to natural gas and renewables

In this scenario, a third of coal-fired power generation is replaced by natural gas and another third is replaced by renewable energy. As in Scenarios 2 and 3, transport sector fuel mixes shift to 50% natural gas in both fleets. There is no reduction in leak rate, which stays at 2.8%. In this scenario, there are high climate benefits across all time frames. Net radiative forcing is reduced by 8.7% and 12.5%, assuming 20 and 100-year time horizons, respectively. As in Scenarios 2, the fuel switch in the transport sector brings climate damages, but these are more than offset by the increased use of renewables.

This is a combination of Scenarios 1 and 4. As in Scenario 4, a third of coal-fired generation is replaced by natural gas and a third is replaced by renewables. Transport sector fuel mixes switch to 50% natural gas in both fleets. Additionally in this scenario, we assume a 6% starting leak rate, which is significantly higher than the 2.8% leak rate based on EPA data (4.9% from the well through the local distribution system plus an additional pump-to-wheels increment of 1.1%). This leak rate of 6% is reduced to 1% across the supply chain. This scenario again illustrates the dramatic increase in climate benefits that results from the reduction of the leak rate, particularly if leak rates are actually higher than those based on EPA data. Net radiative forcing relative to 2010 U.S. greenhouse gas emissions is reduced by 28% and 22% over 20 and 100-year time horizons, respectively. The fuel shift in the transport sector is beneficial to the climate across all time-frames as well, and there are substantial benefits from reducing the leak rate in the non-electricity residential, commercial and industrial sectors.